Attachment device to attach tissue graft

ABSTRACT

A tissue graft attachment device includes a platform member including a leading edge and a trailing edge connected to the leading edge by a pair of sides. The platform member defines a pair of slots extending along a longitudinal axis passing between the leading edge and the trailing edge, and an opening between the pair of slots and the leading edge. The device includes a first suture passing through the opening, a second suture passing through one of the slots, and an attachment member passing through the pair of slots to form a loop. A method for attaching a tissue graft includes providing the tissue graft attachment device, forming a bone tunnel, pulling on the first suture to pull the platform member through the bone tunnel, and pulling on the second suture to position the platform member on the bone tunnel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority from, U.S.application Ser. No. 13/248,635, filed Sep. 29, 2011. The contents ofthe prior application is incorporated herein by reference in theirentirety.

TECHNICAL FIELD

This document relates to tissue graft attachment.

BACKGROUND

An anterior cruciate ligament (ACL) that has ruptured and isnon-repairable is generally replaced arthroscopically by a tissue graft.The tissue graft can be harvested from a portion of a patellar tendonhaving so called “bone blocks” at each end, and from the semitendonosisand gracilis. Alternatively, the tissue graft can be formed fromsynthetic materials or from a combination of synthetic and naturalmaterials.

The replacement tissue graft is implanted by securing one end of thetissue graft in a socket formed in a passage within the femur, andpassing the other end of the graft through a passage formed in thetibia. Generally, sutures are used to affix each end of the tissue graftto a fastener (e.g., an interference screw or a post), which is thensecured to the bone.

A graft fixation member, e.g., a fixation button, can be used to securethe tissue graft at the femoral cortex, as described in U.S. Pat. No.5,306,301 (“the '301 patent”) hereby incorporated by reference in itsentirety. When using a fixation button, the femoral passage generallyincludes a relatively larger diameter portion for receiving the graft,and a smaller diameter, passing channel near the femoral cortex forreceiving a length of suture that runs from the tissue graft to thefixation button. By measuring the total length of the femoral passageand the length of the larger diameter portion of the femoral passage,the surgeon determines the appropriate length of suture material forattaching the fixation button to the tissue graft.

SUMMARY

According to one aspect, a tissue graft attachment device includes aplatform member including a leading edge and a trailing edge connectedto the leading edge by a pair of sides. The platform member defines apair of slots extending along a longitudinal axis passing between theleading edge and the trailing edge, and an opening between the pair ofslots and the leading edge. The tissue graft attachment device includesa first suture passing through the opening, a second suture passingthrough one of the slots, and an attachment member passing through thepair of slots to form a loop.

Implementations of this aspect may include one or more of the followingfeatures.

The pair of sides taper from the trailing edge toward the leading edge.The pair of slots taper from the trailing edge toward the leading edge.The pair of slots are formed on opposite sides of a central axis thatpasses between the leading edge and the trailing edge. The opening isformed on the central axis. The leading edge is substantially curved,for example, substantially semi-circular. The trailing edge issubstantially straight relative to the leading edge. The opening has asubstantially circular cross-section. The attachment member is a thirdsuture or an elastic band.

According to another aspect, a method for attaching a tissue graftincludes providing the tissue graft attachment device, forming a bonetunnel, pulling on the first suture to pull the platform member throughthe bone tunnel, and pulling on the second suture to position theplatform member on the bone tunnel.

Implementations of this aspect may include one or more of the followingfeatures.

The pair of sides taper from the trailing edge toward the leading edge.Forming the bone tunnel further includes forming the bone tunnel tointerfere with the trailing edge. Forming the bone tunnel to interferewith the trailing edge includes forming the bone tunnel to have an innerdiameter that interferes with a dimension of the trailing edge. Pullingon the first suture to pull the tissue graft attachment device throughthe bone tunnel includes pulling the platform member, leading edgefirst, through the bone tunnel. Pulling on the second suture to positionthe platform member on the bone tunnel includes pulling on the secondsuture to position the platform member at an outlet of the bone tunnel.Pulling on the second suture to position the platform member at anoutlet of the bone tunnel includes pulling on the second suture toposition the platform member perpendicular to a longitudinal axis of thebone tunnel at the outlet. The method further includes pulling on thefirst suture to position the platform member on the bone tunnel.

According to yet another aspect, a tissue graft attachment deviceincludes a platform member including a leading edge and a trailing edgeconnected to the leading edge by a pair of sides that taper from thetrailing edge to the leading edge. The platform member defines a pair ofslots extending along a central axis passing between the leading edgeand the trailing edge, and an opening between the pair of slots and theleading edge. The tissue graft attachment device includes an attachmentmember passing through the pair of slots to form a loop.

Implementations of this aspect may include one or more of the followingfeatures.

The tissue graft attachment device includes a first suture passingthrough the opening, and a second suture passing through one of theslots.

According to a further aspect, a tissue graft attachment device includesa platform member including a leading edge and a trailing edge connectedto the leading edge by a pair of sides. The platform member defines apair of slots extending along a longitudinal axis passing between theleading edge and the trailing edge, and a surface bounded by thetrailing edge, an end of the pair of slots, and the pair of sides,wherein the surface does not include an opening. The tissue graftattachment device includes an attachment member passing through the pairof slots to form a loop.

Implementations of this aspect may include one or more of the followingfeatures.

The tissue graft attachment device further includes an opening betweenthe pair of slots and the leading edge.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features,aspects, and advantages will become apparent from the description, thedrawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are illustrations of a tissue graft secured within theknee by a graft attachment device.

FIG. 2 is another view of the knee joint of FIGS. 1A and 1B.

FIG. 3 is a cross-sectional view of a platform member.

FIG. 4 is a perspective view of an attachment device that includes theplatform member of FIG. 3.

FIG. 5A is a perspective view of the attachment device being pulledthrough a bone tunnel.

FIG. 5B is a perspective view of the attachment device of FIG. 5B beingpositioned on the bone tunnel.

FIG. 5C is a perspective view of an attachment device to which a tissuegraft is attached.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

This document describes an example of an attachment device to attachtissue grafts. The attachment device can be implemented in an endoscopictechnique for graft attachment in reconstruction surgery. For example,in an ACL reconstruction surgery, a medial portal incision or atranstibial approach is made and a tunnel is created either from insidethe joint space or from the outside. A tissue graft is attached to aplatform member included in an attachment device, for example, usinglooped sutures or a loop of flexible material. The platform member isthen passed through the tunnel. After the platform member, in itsentirety, exits the tunnel, the attachment device is positioned on thecortex such that the tissue graft passes through the tunnel. A distancebetween a location at which the looped suture is attached to theplatform member and a trailing edge of the platform member may affectthe length of loop suture needed to allow the platform member to exitthe tunnel in its entirety, which may affect an amount of tissue graftthat exits back through the tunnel once the platform member ispositioned on the cortex. In various implementations, this distance isminimized or reduced, which may result in an amount of the tissue graftin the tunnel being maximized because shorter loop sutures can be usedrelative to designs that do not minimize or reduce this distance.Consequently, losses in tissue graft engagement may also be minimized.

Referring to FIGS. 1A and 1B, a knee joint has a tissue graft 10 (e.g.,a patellar tendon graft (FIG. 1A) or a semitendonosis and gracilis graft(FIG. 1B)) implanted in an anterior cruciate ligament (ACL) repair andreconstruction procedure. Prior to implanting tissue graft 10, anotchplasty procedure is preferably performed to expand theintercondylar notch 12 of the femur bone. A femoral channel 14 forreceiving one end of tissue graft 10 is then drilled from notch 12 apredetermined distance within the femur with a passing channel 16 ofreduced diameter drilled further through the femur from femoral channel14 to a region of femoral cortex 18. A tibial channel 20 for receivingthe other end of tissue graft 10 is drilled from an anterior region ofthe tibia to a region near the opening of femoral channel 14.

In the case of patellar tendon graft, one end of tissue graft 10includes a bone block 22 which is shaped and sized in close conformitywith femoral channel 14 to ensure optimal healing. A length of suture 24has one end attached to bone block 22 and the other end secured atfemoral cortex region 18 with an attachment device 26. The suture 24 isa woven or braided suture, for example, #5 Ultrabraid suture, attachedto the attachment device 26 in a loop configuration. In someimplementations described below, one end of the tissue graft 10 isattached to the attachment device 26, which is then pulled through thefemoral channel 14. The attachment device 26 may be configured tomaximize an amount of the tissue graft 10 in the femoral channel 14. Theother end of tissue graft 10 includes a second length of suture 28 whichis attached to the tibia, for example, with a fixation screw 30. Awasher 32 either attached to or positioned under the head of fixationscrew 30 helps in holding the suture in place when screw 30 istightened.

Referring to FIG. 2, length (L) of femoral channel 14 is selected by thesurgeon in accordance with the length of bone block 22 and the desiredinsertion distance of tissue graft 10 within the femur. The span ofsuture 24, designated as SS, is approximately that of passing channel 16so that the sum of the desired insertion length (L) and span of suture(SS) is the measured total length (TL) from the opening of femoralchannel 14 to the opening at femoral cortex 18. Each of these dimensionsis measured prior to implanting the tissue graft so that during theimplantation procedure, the surgeon, under arthroscopic observation, canbe assured that tissue graft 10 has been properly positioned withinfemoral channel 14.

FIGS. 3A and 3B are a plan view and a cross-sectional view,respectively, of an example of a platform member 302 that is included inan attachment device (FIG. 4), for example, the attachment device 26. Asdescribed below, the attachment device includes a platform member 302that defines a pair of slots (a first slot 312 and a second slot 314). Atissue graft is attached to the platform member 302 using an attachmentmember and passed through a bone tunnel, for example, the femoralchannel 14. The platform member 302 is configured to maximize the amountof tissue graft passed through the bone tunnel by allowing an attachmentmember (FIG. 4) to be located close to the trailing edge of the platformmember 302 while the platform member 302 is pulled through a bonetunnel. Consequently, a loss of tissue graft engagement in the bonetunnel can be minimized.

The platform member 302 has a length (L_(p), for example, about 12 mm)and a height (H_(p), for example, 1.5 mm). The platform member 302 has aleading edge 304 and a trailing edge 306 connected to the leading edge304 by a pair of sides (a first side 308 and a second side 310). Thewidth (W_(pl)) of the platform member 302 near the leading edge 304 isless than the width (W_(pt), for example, about 4 mm) near the trailingedge 306. As described below, the trailing edge 306 is configured tointerfere with an inner surface of a bone tunnel, for example, thefemoral channel 14, through which the platform member 302 is pulled. Theleading edge 304 is curved, for example, substantially semi-circularwith a radius of, for example, about 1.75 mm. The trailing edge 306 isless curved relative to the leading edge 304 and is, for example,straight. In alternative implementations, both the leading edge 304 andthe trailing edge 306 can be straight.

The first side 308 and the second side 310 are each substantiallystraight. Further, each side tapers from the trailing edge 306 towardthe leading edge 304. A taper of the first side 308 along a longitudinalaxis 316 (for example, a central axis) passing between the leading edge304 and the trailing edge 306 can be the same as or different from ataper of the second side 310 along the longitudinal axis 316. In someimplementations, one of the pair of sides (either the first side 308 orthe second side 310) can be parallel to the longitudinal axis 316 andthe other may not, while in other implementations, the first side 308and the second side 310 can be parallel to each other and to thelongitudinal axis 316.

The platform member 302 defines a pair of slots (a first slot 312 and asecond slot 314) extending along the longitudinal axis 316. Each slot312, 314 is formed on a top surface 320 of the platform member 302 andspans the height of the platform member 302 from the top surface 320 tothe bottom surface 322. As described below, each slot 312, 314 isdefined by a respective inner trailing edge 332, 340. The inner trailingedges 332, 340 may be formed as near the trailing edge 306 of theplatform member 302 as possible, taking into account, for example,machining and manufacturing tolerances, as well as structural integrity.During use, this may minimize or reduce the length of loop suture orother attachment member used to hold the graft.

The first slot 312 is defined by an inner leading edge 330 and an innertrailing edge 332 connected by a pair of inner sides (a first inner side326 and a second inner side 328). A length of the first slot 312 fromthe inner leading edge 330 to the inner trailing edge 332 can be, forexample, about 7.73 mm. A width of the first slot 312 near the innerleading edge 330 is less than a width near the inner trailing edge 332.In some implementations, the width of the first slot 312 is sufficientto pass the attachment member (FIG. 4) or a suture (FIG. 4) or boththrough the first slot 312. Each of the inner leading edge 330 and theinner trailing edge 332 is curved and, for example, has a semi-circularcross-section. For example, a radius of curvature of the inner leadingedge 330 and the inner trailing edge is about 0.38 mm and 0.51 mm,respectively. Alternatively, one or both of the first inner leading edge330 and the inner trailing edge 332 can be straight.

The first inner side 326 and the second inner side 328 are formedbetween the longitudinal axis 316 and the first side 308 such that thefirst inner side 326 is closer to the first side 308 than to thelongitudinal axis 316, and the second inner side 328 is closer to thelongitudinal axis 316 than to the first side 308. In someimplementations, the first inner side 326 is parallel to thelongitudinal axis 316 and the second inner side 328 is parallel to thefirst side 308. Because the first side 308 tapers from the trailing edge306 toward the leading edge 304 along a longitudinal axis 334 of thefirst slot 312, in such implementations, the first inner side 326 andthe second inner side 328 may not be parallel to each other.Alternatively, each of the pair of inner sides 326, 328 can be parallelto each other and to either the first side 308 or the longitudinal axis316.

The second slot 314 is formed on the platform member 302 in a mannersimilar to the first slot 312 but on the opposite side of thelongitudinal axis 316. In some implementations, the second slot 314 is amirror image of the first slot 312 about the longitudinal axis 316, andis defined by an inner leading edge 338 and an inner trailing edge 340connected by a pair of inner sides (a first inner side 342 and a secondinner side 344) along the longitudinal axis 316. The trailing edge 306,an end of the pair of slots 312, 314, and the pair of sides 308, 310define a surface 350 that does not include an opening. For example, thesurface 350 is bounded by the trailing edge 306, the inner trailingedges 332, 340 of the pair of slots 312, 314, and the pair of sides 308,310.

The platform member 302 additionally defines an opening 318 between thepair of slots 312, 314 and the leading edge 304. The opening 318 isformed on the top surface 320 of the platform member 302 and spans aheight of the platform member 302 from the top surface 320 to the bottomsurface 322. In some implementations, the opening 318 is formed on thelongitudinal axis 316. The opening 318 has a substantially circularcross-section. In alternative implementations, the cross-section of theopening 318 can be, for example, rectangular, elliptical, and the like.A cross-sectional dimension of the opening 318 is sufficient to receivea suture to pull the platform member 302 through the bone tunnel. Forexample, a diameter of the opening 318 can be about 1 mm.

FIG. 4 is a perspective view of an attachment device 400, which includesthe platform member 302 and an attachment member 324 passing through thepair of slots (the first slot 312 and the second slot 314) to form aloop. The attachment member 324 can be made from a flexible materialthat can be formed into a loop. For example, the attachment member 324can be approximately 10 mm long in an un-stretched state andapproximately 50 mm long in a stretched state. In some implementations,the attachment member 324 is a suture, while, in others, the attachmentmember 324 is an elastic band. An end of the tissue graft is attached tothe loop (324). A length of the attachment member 324 may be chosen suchthat the end of the tissue graft is located as close to the platformmember 302 as possible, while still allowing the platform member 302 toexit the bone tunnel. This may maximize a length of engagement of thetissue graft.

In some implementations, the attachment device 400 can be pre-loaded toinclude a first suture 402 and a second suture 404. Specifically, thefirst suture 402 is passed through the opening 318 and the second suture404 is passed through either the first slot 312 or the second slot 314or, in some situations, looped through both slots 312 and 314. In someimplementations, the platform member 302 may not define an openingbetween the pair of slots 312, 314 and the leading edge 304. In suchimplementations, the first suture 402 and the second suture 404 can bepassed through either the first slot 312 or the second slot 314, orboth.

FIGS. 5A and 5B are perspective views of the attachment device 400 towhich a tissue graft 520 is attached, being pulled through andpositioned on a bone tunnel 500, for example, the femoral channel 14.The bone tunnel 500 can be, for example, 3.5 mm in diameter and have asubstantially vertical or angular orientation. A tissue graft 520 isattached to the attachment member 324. The attachment device 400 is thenpassed through the bone tunnel 500. To do so, the first suture 402,which was passed through the opening 318, is pulled through the bonetunnel 500, causing the leading edge 304 of the platform member 302 tofirst pass through the bone tunnel 500 followed by the trailing edge306. The attachment member 324 that is passed through the pair of slots312, 314 trails the leading edge 306. Because the tissue graft 520 isattached to the loop (324), pulling on the first suture 402 causes thetissue graft 520 to be passed through the bone tunnel 500. Similarly,because the second suture 404 is attached to the either or both slots312, 314, pulling on the first suture 402 also causes the second suture404 to be passed through the bone tunnel 500.

As the platform member 302 is pulled through the bone tunnel 500, theloop (324) slides towards and rests against the inner trailing edges332, 340 of the first slot 312 and the second slot 314, respectively. Asdescribed above, the inner trailing edge 332 of the first slot 312 andthe inner trailing edge 340 of the second slot 314 may each be formed asnear the trailing edge 306 as possible. Because the loop (324) moves tothe inner trailing edge 340, the length of loop (324) needed is shorterthan if the loop (324) was connected elsewhere on the platform member(for example, the center). This is the result of the loop (324) needingto be longer at other attachment points to allow the platform member 302to fully exit the tunnel 500. A shorter loop (324) can result in agreater engagement of the tissue graft with the bone when compared to alonger loop (324).

When the platform member 302 exits the outlet 502 of the bone tunnel500, the inner trailing edges 332, 340 first exit the outlet 502followed by the trailing edge 306. The second suture 404 can be pulledout of the outlet 502. After the platform member 302 exits the outlet inits entirety, the platform member 302 is positioned on a bone surface504 of the bone tunnel 500, for example, the cortex of the femoralchannel 14. To do so, the platform member 302 is flipped until a portionof either the top surface 320 or the bottom surface 322 rests on thebone surface 504. As shown in FIG. 5B, the second suture 404 is pulled,for example, in a direction transverse to a longitudinal axis of thebone tunnel 500, to position the platform member 302 on the bone surface504. For example, after the platform member 302 has been flipped andrested on the bone surface 504, either the first suture 402 or thesecond suture 404 or both can be pulled to slide the platform member 302on the bone surface 504 until the platform member 302 is substantiallycentered in the bone tunnel 500. Once positioned, the longitudinal axis316 of the platform member 302 can be perpendicular to a longitudinalaxis of the bone tunnel 500. FIG. 5C is a perspective view of anattachment device 400 to which a tissue graft 520 is attached. Bysliding the platform member 302 using either the first suture 402 or thesecond suture 404 or both along the bone surface 504, the position ofthe tissue graft 520 in the bone tunnel 500 can be centered.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyimplementations or of what may be claimed, but rather as descriptions offeatures specific to particular implementations of particularimplementations. Certain features that are described in thisspecification in the context of separate implementations can also beimplemented in combination in a single implementation. Conversely,various features that are described in the context of a singleimplementation can also be implemented in multiple implementationsseparately or in any suitable subcombination. Moreover, althoughfeatures may be described above as acting in certain combinations andeven initially claimed as such, one or more features from a claimedcombination can in some cases be excised from the combination, and theclaimed combination may be directed to a subcombination or variation ofa subcombination. Thus, particular implementations of the subject matterhave been described. Other implementations are within the scope of thefollowing claims.

The invention claimed is:
 1. A tissue graft attachment devicecomprising: a platform member having a central axis and including aleading edge and a trailing edge connected to the leading edge by a pairof sides, the platform member defining: i) a pair of elongated slotsextending along the central axis between the leading edge and thetrailing edge, the elongated slots being located on opposite sides ofthe central axis and positioned to form a central member in-line withthe central axis, each elongated slot comprising a respective innerleading edge; and ii) one and only one circular opening defined in theplatform member, the one and only one circular opening positionedin-line with the central axis between the inner leading edges of theelongated slots in the pair of elongated slots and the platform leadingedge; a first suture passing through the circular opening; a secondsuture passing through one of the elongated slots; and an attachmentmember passing through each elongated slot in the pair of elongatedslots and forming a loop around the central member.
 2. The device ofclaim 1, wherein the leading edge is substantially curved; and wherein alength of the elongated slots along the central axis is greater than awidth of the attachment member, the attachment member free to move inthe elongated slots along the central member.
 3. The device of claim 1,wherein the leading edge is substantially semi-circular.
 4. The deviceof claim 1, wherein the attachment member is an elastic band.
 5. Thedevice of claim 1, wherein an outer surface of the sides of the platformmember are smooth to facilitate passage of the platform member through abone tunnel.
 6. The device of claim 5, wherein the first suture and thesecond suture facilitate orientation of the central axis in a directiontransverse to a longitudinal axis of a bone tunnel through which theplatform member is pulled, a tissue graft coupled to the attachmentmember, the attachment member extending through the bone tunnel.
 7. Thedevice of claim 6, wherein the platform member rests on a surface of thebone over the bone tunnel, the platform member anchored with respect tothe surface the bone tunnel.
 8. A method of attaching a tissue graft,the method comprising: providing a tissue graft attachment device thatincludes: a platform member having a central axis and including aleading edge and a trailing edge connected to the leading edge by a pairof sides, the platform member defining: a pair of elongated slotsextending along the central axis between the leading edge and thetrailing edge, the elongated slots being located on opposite sides ofthe central axis and positioned to form a central member in-line withthe central axis, each elongated slot comprising a respective innerleading edge; and one and only one circular opening defined in theplatform member, the one and only one circular opening positionedin-line with the central axis between the inner leading edges of theelongated slots in the pair of elongated slots and the platform leadingedge, a first suture passing through the circular opening, a secondsuture passing through one of the elongated slots, and an attachmentmember passing through each of the elongated slots in the pair andforming a loop around the central member; forming a bone tunnel; pullingon the first suture to pull the platform member through the bone tunnel;and pulling on the second suture to position the platform member on thebone tunnel.
 9. The device of claim 1, wherein the pair of elongatedslots includes a first elongated slot and a second elongated slot, thesecond suture passing through the first elongated slot, the attachmentmember passing through both the first elongated slot and the secondelongated slot to form the loop; wherein the first elongated slotincludes a first end and a second end, the first end located towards theleading edge, the second end located towards the trailing edge; andwherein the second suture resides at the second end of the firstelongated slot.
 10. The device as in claim 9, wherein the loop formed bythe attachment member resides in a middle of the first elongated slotbetween the first end and the second end.
 11. The tissue graftattachment device as in claim 1, wherein the platform isarrowhead-shaped.
 12. The tissue graft attachment device as in claim 11,wherein the pair of elongated slots includes a first elongated slot anda second elongated slot, the first elongated slot narrowing fromtrailing edge to the leading edge, the second elongated slot narrowingfrom the trailing edge to the leading edge.
 13. The tissue graftattachment device of claim 1, wherein each elongated slot furthercomprises: a respective inner leading edge, first and second inner sidesand an inner trailing edge, wherein the first inner sides are parallelto the central axis and the second inner sides are not parallel to thecentral axis.
 14. The tissue graft attachment device of claim 1,wherein: each elongated slot further comprises a respective innertrailing edge, wherein each respective inner trailing edge is formed asnear the platform member trailing edge as is possible.
 15. The methoddevice of claim 8, wherein the pair of elongated slots includes a firstelongated slot and a second elongated slot, the second suture passingthrough the first elongated slot, a length of the attachment memberpassing through both the first elongated slot and the second elongatedslot; wherein the first elongated slot includes a first end and a secondend, the first end located towards the leading edge, the second endlocated towards near the trailing edge; and wherein the second sutureresides at the second end of the first elongated slot.
 16. The method ofclaim 8, wherein the pair of sides taper from the trailing edge towardthe leading edge, and wherein forming the bone tunnel further comprisesforming the bone tunnel to interfere with the trailing edge.
 17. Themethod of claim 16, wherein forming the bone tunnel to interfere withthe trailing edge comprises forming the bone tunnel to have an innerdiameter that interferes with a dimension of the trailing edge.
 18. Themethod of claim 16, wherein pulling on the first suture to pull thetissue graft attachment device through the bone tunnel comprises pullingthe platform member, leading edge first, through the bone tunnel. 19.The method of claim 8, wherein pulling on the second suture to positionthe platform member on the bone tunnel comprises pulling on the secondsuture to position the platform member at an outlet of the bone tunnel.20. The method of claim 19, wherein pulling on the second suture toposition the platform member at an outlet of the bone tunnel comprisespulling on the second suture to position the platform memberperpendicular to a longitudinal axis of the bone tunnel at the outlet.